This invention relates to heat sinks and particularly to the means for attaching them to semiconductor devices.
Heat sinks commonly are attached to electronic devices (e.g., integrated circuits) to dissipate the heat which the devices generate during operation. In order to do this, the heat sinks are designed to have a maximum surface area, the size of which determines their heat dissipating capacity, while still occupying the smallest possible volume so that the heat sink takes up as little usable space as possible in the electronic assembly.
Most heat sinks have flat surfaces called fins to dissipate the heat, and one type of heat sink, called a "pin-fin" heat sink, comprises a matrix of separate pins that extend from a backing plate. In each case, the metal fins or pins serve as the heat-dissipating means for the heat sink. In many cases, the side of the backing plate opposite the fins or pins is adapted to be mounted or otherwise secured to the electronic device to be cooled. During operation, the heat sink may be further cooled by blowing air vertically or horizontally over and between the fins or pins. As most of these finished heat sinks are then secured to a semiconductor package by an adhesive applied to the backing plate opposite the pins, the heat sinks are difficult to remove, which removal is desirable whenever the semiconductor needs to be replaced.